The most common male masturbation technique is simply to hold the penis with a loose fist and then to move the hand up and down the shaft. This technique is also used by some men who are circumcised who have excess skin left from circumcision. Among swinging couples, one of the two partners is often the driving force and the other is more passive-supportive of the addition of additional sex parties. A related term used in the genre is the term cougar, which implies an older woman as predator. When used as an alternative to penile-vaginal penetration, the goal may be to preserve virginity or to prevent pregnancy. No causal relationship is known between masturbation and any form of mental or physical disorder. In these research publications, it is suggested that real female ejaculation is the release of a very scanty, thick, and whitish fluid from the female prostate, while the squirting or gushing shown frequently in pornography lesbian milfs is a different phenomenon, the expulsion of clear and abundant fluid, which has been shown to be a diluted fluid from the urinary bladder. In contrast, a celebrity may take the route of openly releasing the tape and benefit directly from royalties as well as indirectly from the publicity. Lolita pornography hentai movies caters to ephebophiles. Reading or viewing pornography, sexual fantasy or other erotic stimuli may lead to a desire for sexual release such videos gays as by masturbation. The activity is done by itself or as a part of or prelude to other activities which many times involve sex. Nevertheless, it is only an attempt at phenomenological differentiation. Some people get sexual pleasure by inserting objects, such as urethral sounds, into the urethra , a practice known as urethral play or sounding. Creampie, also known as internal cum shot, and, in homosexual contexts, also known as breeding and seeding, is a slang term used in pornography to describe when a male ejaculates inside his partner vagina or anus. Reality and voyeur pornography, animated videos, and legally prohibited acts also influence the classification of pornography.